Plug-in scr lamp dimmer with wall switch and socket



Aug. 4, 1970 R. M. MURPHY PLUG I" 50R LAMP DIIIIER WITH WALL SWITCH ANDSOCKET Filed Feb. 15,1968

2 Sheets-Sheet l WIINVENTOR. Q

. JII'IORNEYS.

g- 1970 R. M. MURPHY 3,523,212

PLUG IN 503' LAMP DIMMER WITH WALL SWITCH AND SOCKET Filed Feb. 15, 19682 Sheets-Sheet 2 4 51 4 -44 #6 73,7 36 M j 1,40 1e "I Ml w ""1 \i 2 um"mind I .1 f hi Hind I 22 ii 1/ I a I INVENTQR.

43 42 18 2 16 BYM M nrroma'zs.

United States Patent Office 3,523,212 Patented Aug. 4, 1970 PLUG-IN SCRLAMP DIMMER WITH WALL SWITCH AND SOCKET Robert M. Murphy, Fairfield,Conn., assiguor to Harvey Hubbell, Incorporated, Bridgeport, Coun., acorporaw tion of Connecticut Filed Feb. 15, 1968, Ser. No. 705,712 Int.Cl. H01r 31/08; H01b 37/02, 39/04 U.S. Cl. 315-291 9 Claims ABSTRACT OFTHE DISCLOSURE A portable dimmer system having a wall mountable unitincluding a switch and special receptacle and a portable dimmer unitwhich may be selectively engaged with the special receptacle. Thereceptacle includes usual receptacle contacts which are shorted by meansof selectively operable shorting contacts and the dimmer unit includes ahoused dimmer circuit electrically connected to usual contact blades anda non-conductive operable blade insertable into the special receptacleto open the shorting contacts to allow current to flow through thedimmer circuit when the switch is closed.

BACKGROUND OF THE INVENTION This invention relates to a light dimmingsystem and more particularly to a portable device which may be utilizedwith special receptacles to selectively control the light intensity ofseveral sets of fixtures.

In recent years it has become extremely popular in private homes tolower the ambient light level in various rooms of the house. Severaltypes of dimmers are available for varying the intensity of incandescentlighting. One type includes a socket which itself receives anincandescent bulb and which may be mounted in a usual lamp socket. Thisunit houses suitable circuitry to enable the light intensity of thesingle bulb to be controlled. Also known is the permanently installeddimmer control unit which may be wall mounted in place of a usual wallmounted ON-OFF switch. This relatively expensive unit allows thehomeowner to select either the maximum intensity ON position, the OFFposition and a range of DIM positions. In a modern house, it would notbe uncommon to find on the order of ten different lighting fixtureselectrically connected so that they may be directly controlled by one ormore switches. Therefore, it would run to considerable expense toprovide each of these fixtures with a dimmer or to substitute apermanent dimmer Wall unit for each of the switches. Where dimming isused fairly often as in a dining or living room it may be advisable topermanently install a dimming unit as described above. However,depending upon the location of the other fixtures the desirability andneed to operate these with a dimming device would vary from very oftento very rarely. For instance, in a childs bedroom it becomes desirableto utilize a dimmer to maintain a low ambient level of light presentduring periods of illness. This would normally be an extremely rareoccurrence and would hardly justify permanent installation of a dimmerunit as the most convenient means of providing a reduced ambient lightlevel.

SUMMARY OF THE INVENTION Accordingly, it is the primary object of myinvention to provide a dimming system including a single portable dimmerto be used together with one of several unique switch and receptacleunits to selectively dim various fixtures as the need arises.

Another object is to provide an inexpensive, unique switch andreceptacle device which would operate in the manner of a usual ON-OFFswitch in the absence of the portable dimmer and in which the specialreceptacle will accept the portable dimmer to allow the dimmer circuitryto control the lighting fixture.

To accomplish these objects, in one form a portable dimmer system isprovided which comprises: a wall mountable unit including light switchmeans and receptacle means electrically connected in series therewith,receptacle contact members, and means for short circuiting thereceptacle contact members, positioned within the receptacle andselectively operable to open the short circult; and a portable dimmerunit selectively engageable with the receptacle including a housing,dimming circuit means located within the housing, dimmer control meanscarried by the housing, contact means for insertion into the receptacleto engage the receptacle contact members and electrically connected tothe dimming circuit means, and operator means for insertion into thereceptacle to cooperate with the short circuiting means to open theshort circuit.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and further details ofthat which I believe to be novel and my invention will be clear from thefollowing description and claims taken with the accompanying drawingswherein:

FIG. 1 is a schematic electrical wiring diagram showing the load circuitwith the unique switch and receptacle located therein and the dimmingcircuit with its plug aligned with the special receptacle;

FIG. 2 is a front elevational view showing the face plate of the uniqueswitch and receptacle unit with the portable dimmer shown connectedthereto, being illustrated in dotdash lines;

FIG. 3 is a front elevational view of the portable dimmer;

FIG. 4 is a transverse sectional view taken through the receptacle withthe portable dimmer aligned to be connected thereto; and

FIG. 5 is a sectional view similar to that of FIG. .4 showing theportable dimmer connected with the special receptacle.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to the drawings,there is illustrated in FIG. 1 my unique switch and receptacle unitindicated generally by the numeral 10. The unit 10 may be wall mountedin the manner of a usual ON-OFF switch and is wired in series with alighting fixture F in the electric power supply line between terminals Land N. It includes a single-pole, single-throw AC switch 12 wired inseries with a special receptacle 14 having two usual receptacle contacts16 and central shorting contacts 18.

The special receptacle 14, clearly shown in detail in FIGS. 4 and 5comprises a housing 20 made of a suitable electrical insulating materialdesigned to be mounted upon a metal strap 22 so that its face 24protrudes through an opening in the strap 22 and an aligned opening in awall plate 25. The switch 12 is mounted upon the metal strap 22 in asimilar manner, with its toggle lever 26 also extending through anotheropening in the strap 22 and another aligned opening in the wall plate25. Three slots 28, 30 and 32 defined through the face 24 communicatethe exterior of the receptacle housing with the interior chamber 34.Disposed within the chamber are the two sets of usual receptaclecontacts 16 and the central shorting contacts 18 which are aligned withthe slots 28, 30 an 32, respectively.

A terminal plate 36 positioned on the hot side of the line, is mountedin the slot 37 formed in one side wall of the housing. In a like manner,terminal plate 38 is secured in the housing on the neutral side of theline. The shorting contacts 18 comprise two generally L-shaped strips ofa suitable spring metal each having one leg 40 and 42 secured to itsrespective terminal plate and each carrying one of the receptaclecontacts 16. Binding head screws 44 and 46 are threadedly engaged in theterminal plates 36 and 38 to secure current carrying wires to thespecial receptacle. A closure plate 48 located at the rear of thehousing to maintain the contacts 16 and 18 in position in the chamber 34and prevent entry of foreign objects is held in place by a suitableretaining strap 50. A connecting wire 51 captured by the binding headscrew 44 electrically connects the switch 12 to the special receptacle14 as shown schematically in FIG. 1.

A portable dimmer unit 52 may 'be selectively used in conjunction withany one of the wall mounted unique switch and receptacle units 10 tocontrol and intensity of any of the lighting fixtures F. The unit 52includes a relatively small rectangular housing 54, preferably made of aplastic material, having a special three bladed plug 56 extending fromone face thereof and a rotatable wheel 58 extending outwardly from theopposite face thereof. The housing confines suitable dimmer circuitrysuch as that schematically represented in FIG. 1 which is more fullydescribed in copending application of Misencik and Lee for patent forPhase Controlled Alternating Current Circuit, filed Aug. 8, 1966, SerNo. 570,798, assigned to the assignee of the instant application.

The plug 56 includes the usual metal power blades 60 and 62 and ashorter, central operator blade 64 which is made of a non-conductiveplastic material. With reference to FIGS. 1, 4 and it should beunderstood that as the power blades 60 and 62 are passed through theslots 28 and 30 into the receptacle contacts 16 they initially connectthe dimmer circuitry across the supply line in parallel with the shuntformed by the shorting contacts 18. As the plug 56 is further inserted,the operator blade 64 will urge the shorting contacts apart, to allowthe dimmer circuitry to control the lighting fixture F. On removal ofthe portable dimmer unit 52 from the special receptacle 14 the sequencewould be in reverse to allow the shorting contacts to close prior to theloss of electrical contact of the power blades 60 and 62 with thereceptacle contacts 16 (note FIG. 5). This sequential control of theshorting contacts 18 relative to the receptacle contacts 16 serves atwo-fold function. It provides protection from full power surges to thedimmer circuitry should the portable dimmer unit be inserted in orwithdrawn from the special receptacle while the series connected switch12 is in a closed position. This sequence also provides protection tothe receptacle contacts 16 from arcing.

The unique switch and receptacle unit is relatively inexpensive,approaching the cost of a single ON-OFF switch which it would replace.As shown in FIG. 2 the wall plate 25 exposes the switch toggle lever 26and the special receptacle face 24 which receives the portable dimmerunit 52 (note dot-dash lines). Once unit 52 is mounted in place, thedimmer wheel 58 may be selectively rotated in either a clockwise oncounter-clockwise direction to vary the light intensity of the lightingfixture F and the switch 12 may still be used to provide a positiveturnoii. In the absence of the portable dimmer unit, the shortingcontacts 18 allow the unique switch and receptacle unit 10 to operate inthe manner of a usual ON-OFF switch. It should be apparent to thoseskilled in this art that the shorting contacts housed in the specialreceptacle operate as a mechanical switch and may take other forms. andmay be controlled by any of various types of mechanical operatorscarried by the portable dimmer unit.

It is believed that the many advantages of this invention may now beapparent to those skilled in the art. As

set forth in the objects above I have provided a low cost portabledimmer unit which may be used in conjunction with any one of a number ofunique switch and receptacle units which would replace the usual wallmounted switches so that the user may have complete flexibility ofchoice as to which lighting fixtures would be dimmed.

It should be understood that the present disclosure has been made onlyby way of example and that numerous changes in details of constructionand the combination and arrangement of parts may be resorted to withoutdeparting from the true spirit and the scope of the invention ashereinafter claimed.

What is claimed is:

1. A wall mountable unit comprising: a wall plate; a light switchcarried by said wall plate and having first and second electricalterminals for receiving electrical current carrying wires; a receptaclecarried by said wall plate and having first and second electricalterminals, a first receptacle contact member electrically connected tosaid first terminal, a second receptacle contact member electricallyconnected to said second terminal, means for normally electrically shortcircuiting said first and second terminals being selectively operable toopen the short circuit; and electrical conductor means connecting saidsecond switch terminal with said first receptacle terminal to place saidswitch in series with said receptacle.

2. The wall mountable unit defined in claim 1 wherein: said receptaclecomprises a housing; said short circuiting means includes a pair ofspring metal contacts each having one end normally biased against saidother contact, the other ends of said spring metal contacts beingsecured to said receptacle terminals.

3. The wall mountable unit defined in claim 2 wherein said housingincludes a plurality of slots formed in one face thereof, said slotsbeing aligned with said receptacle contacts and said short circuitingmeans.

4. A portable dimmer unit selectively engageable with a wall mountedreceptacle, comprising: a housing; dimming circuit means positionedwithin said housing; selectively operable dimmer control means mountedon said housing; contact means for insertion into the receptableextending outwardly from said housing and being electrically connectedto said dimming circuit means; and operator means for actuating a switchwhen said portable dimmer unit is engaged with the receptacle.

5. The portable dimmer unit defined in claim 4 wherein: said dimmercontrol means comprises a rotatable dimmer wheel positioned upon oneface of said housing; and said contact means includes a plug havingblades positioned upon another face of said housing for insertion intothe receptacle contacts of the receptacle.

6. The portable dimmer unit defined in claim 4 wherein said operatormeans extends outwardly from said housing and comprises a blade formedon a non-metallic, insulating material.

7. The portable dimmer unit defined in claim 6 wherein: said contactmeans includes a plug having blades positioned upon another face of saidhousing for insertion into the receptacle contacts of the receptacle;and said operator blade is shorter than said contact blades.

8. A portable dimmer system comprising: a wall mountable unit includinglight switch means and receptacle means electrically connected in seriestherewith, said receptacle means housing receptacle contact members andmeans for electrically short circuiting said receptable contact membersbeing selectively operable to open the short circuit; and a portabledimmer unit selectively engageable with said receptacle including ahousing, dimming circuit means located within said housing, dimmercontrol meant carried by said housing, contact means for insertion intosaid receptacle to engage said receptacle contact members and beingelectrically connected to said dimming circuit means, and operator meansfor insertion into said receptacle to cooperate with said shortcircuiting means to open the short circuit, whereby, when said portabledimming unit is engaged with said receptacle, electrical current mustpass from said switch through said dimming circuit means to control anelectrically connected lighting fixture.

9. The portable dimmer system defined in claim 8 wherein: saidreceptacle includes a housing having a plurality of slots formedtherein; said receptacle contacts and said short circuiting means beingaligned with said slots; said dimmer unit contact means includes a plughaving blades extending outwardly from one face of said dimmer unit forinsertion through said slots to engage said receptacle contacts; andsaid operator means includes a plastic blade extending outwardly fromsaid one face of said dimmer unit for insertion through one of saidslots.

References Cited UNITED STATES PATENTS Slater 323-22 Willett ZOO-51.1 XVoss 315-320 X Carpenter 315-291 X Morton 315-205 Leichenring ZOO-51.1 XCunningham 323-22 JAMES W. LAWRENCE, Primary Examiner C. R. CAMPBELL,Assistant Examiner US. Cl. X.R.

ZOO-51.1; 307-305; 315-205; 323-24

